diff --git a/src/bootstrap/src/core/build_steps/llvm.rs b/src/bootstrap/src/core/build_steps/llvm.rs
index 7e1b59351e042..a591be05291fa 100644
--- a/src/bootstrap/src/core/build_steps/llvm.rs
+++ b/src/bootstrap/src/core/build_steps/llvm.rs
@@ -206,7 +206,6 @@ pub(crate) fn is_ci_llvm_available_for_target(
         ("aarch64-unknown-linux-gnu", false),
         ("aarch64-apple-darwin", false),
         ("aarch64-pc-windows-msvc", false),
-        ("i686-pc-windows-gnu", false),
         ("i686-pc-windows-msvc", false),
         ("i686-unknown-linux-gnu", false),
         ("x86_64-unknown-linux-gnu", true),
@@ -215,9 +214,11 @@ pub(crate) fn is_ci_llvm_available_for_target(
         ("x86_64-pc-windows-msvc", true),
         // tier 2 with host tools
         ("aarch64-unknown-linux-musl", false),
+        ("aarch64-pc-windows-gnullvm", false),
         ("arm-unknown-linux-gnueabi", false),
         ("arm-unknown-linux-gnueabihf", false),
         ("armv7-unknown-linux-gnueabihf", false),
+        ("i686-pc-windows-gnu", false),
         ("loongarch64-unknown-linux-gnu", false),
         ("loongarch64-unknown-linux-musl", false),
         ("powerpc-unknown-linux-gnu", false),
@@ -226,6 +227,7 @@ pub(crate) fn is_ci_llvm_available_for_target(
         ("powerpc64le-unknown-linux-musl", false),
         ("riscv64gc-unknown-linux-gnu", false),
         ("s390x-unknown-linux-gnu", false),
+        ("x86_64-pc-windows-gnullvm", true),
         ("x86_64-unknown-freebsd", false),
         ("x86_64-unknown-illumos", false),
         ("x86_64-unknown-linux-musl", false),
diff --git a/src/bootstrap/src/core/download.rs b/src/bootstrap/src/core/download.rs
index a096d116e73fa..d950dc1a1c582 100644
--- a/src/bootstrap/src/core/download.rs
+++ b/src/bootstrap/src/core/download.rs
@@ -447,6 +447,7 @@ pub(crate) fn is_download_ci_available(target_triple: &str, llvm_assertions: boo
     // All tier 1 targets and tier 2 targets with host tools.
     const SUPPORTED_PLATFORMS: &[&str] = &[
         "aarch64-apple-darwin",
+        "aarch64-pc-windows-gnullvm",
         "aarch64-pc-windows-msvc",
         "aarch64-unknown-linux-gnu",
         "aarch64-unknown-linux-musl",
@@ -465,6 +466,7 @@ pub(crate) fn is_download_ci_available(target_triple: &str, llvm_assertions: boo
         "s390x-unknown-linux-gnu",
         "x86_64-apple-darwin",
         "x86_64-pc-windows-gnu",
+        "x86_64-pc-windows-gnullvm",
         "x86_64-pc-windows-msvc",
         "x86_64-unknown-freebsd",
         "x86_64-unknown-illumos",